Propagate viewport intersection across OOPIFs at the correct time

Propagate viewport intersection across OOPIFs at the correct time

This corrects a couple of issues with how viewport intersection rects
were being sent to OOPIF processes from their parents, which was causing
frame throttling bugs:

1. The update is now triggered from the parent FrameView's
UpdateViewportIntersectionsForSubtree, rather than the RemoteFrameView's
frameRectsChanged. Formerly, this would cause intersection calculations
in a dirty layout tree, and also fail to propagate intersection rect
changes in the case of nested OOPIFs.

2. Viewport intersections are now updated properly when the iframe
is scrolled off of screen. Previously it would return early when an
OOPIF had no viewport intersection, which was wrong.

BUG=682307, 712320
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2860903003
Cr-Commit-Position: refs/heads/master@{#469977}
(cherry picked from commit 321a171abcca381e3ef72d01996e4ae4dd860212)

Review-Url: https://codereview.chromium.org/2873083002 .
Cr-Commit-Position: refs/branch-heads/3071@{#489}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/c4999457b7f0e7121f4067d9bdf86a93299a8c94

[Charlie Reis, 2017-05-09 23:05:16]

creis@chromium.org changed reviewers:
+ dcheng@chromium.org, kenrb@chromium.org

[Charlie Reis, 2017-05-09 23:05:16]

FYI: Merging to M59.

[Charlie Reis, 2017-05-09 23:05:55]

Description was changed from

==========
Propagate viewport intersection across OOPIFs at the correct time

This corrects a couple of issues with how viewport intersection rects
were being sent to OOPIF processes from their parents, which was causing
frame throttling bugs:

1. The update is now triggered from the parent FrameView's
UpdateViewportIntersectionsForSubtree, rather than the RemoteFrameView's
frameRectsChanged. Formerly, this would cause intersection calculations
in a dirty layout tree, and also fail to propagate intersection rect
changes in the case of nested OOPIFs.

2. Viewport intersections are now updated properly when the iframe
is scrolled off of screen. Previously it would return early when an
OOPIF had no viewport intersection, which was wrong.

BUG=682307, 712320
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2860903003
Cr-Commit-Position: refs/heads/master@{#469977}
(cherry picked from commit 321a171abcca381e3ef72d01996e4ae4dd860212)
==========

to

==========
Propagate viewport intersection across OOPIFs at the correct time

This corrects a couple of issues with how viewport intersection rects
were being sent to OOPIF processes from their parents, which was causing
frame throttling bugs:

1. The update is now triggered from the parent FrameView's
UpdateViewportIntersectionsForSubtree, rather than the RemoteFrameView's
frameRectsChanged. Formerly, this would cause intersection calculations
in a dirty layout tree, and also fail to propagate intersection rect
changes in the case of nested OOPIFs.

2. Viewport intersections are now updated properly when the iframe
is scrolled off of screen. Previously it would return early when an
OOPIF had no viewport intersection, which was wrong.

BUG=682307, 712320
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2860903003
Cr-Commit-Position: refs/heads/master@{#469977}
(cherry picked from commit 321a171abcca381e3ef72d01996e4ae4dd860212)

Review-Url: https://codereview.chromium.org/2873083002 .
Cr-Commit-Position: refs/branch-heads/3071@{#489}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/c4999457b7f0e7121f4067d9bdf8...
==========

[Charlie Reis, 2017-05-09 23:05:57]

Committed patchset #1 (id:1) manually as
c4999457b7f0e7121f4067d9bdf86a93299a8c94.